Virtual reality (VR) offers great potential for studies of craving in drug abusers. By immersing subjects in realistic-looking environments, it is possible to provide stimulus cues of the experimenter's choosing and timing to elicit more controlled reactions from subjects. When combined with neuroimaging studies such as functional magnetic resonance imaging (fl\4RI), VR will provide an unprecedented opportunity to study brain activation in situations much more closely approximating real-life. A number of sensory systems can be activated simultaneously to provide a rich multi modal simulation that is more likely to arouse craving that resembles what the subject experiences outside of the contrived situations available in most laboratories. Our goal is to provide a flexible tool for drug-abuse researchers interested in studying virtual reality simulations, especially in the context of fMRI studies. We intend to tailor the project to cigarette smokers for this particular proposal, but the techniques used will allow the application to be generalized to studies of other populations of drug abusers without much difficulty. Phase I funds will allow us to modify an existing VR application for studies of cigarette craving and test the hypothesis that well-positioned craving cues within the simulation will elicit sufficient brain activation that can be detected during fMRI studies.